Waiting for PostgreSQL 19 – json format for COPY TO

On 20th of March 2026, Andrew Dunstan committed patch:

json format for COPY TO
 
This introduces the JSON format option for the COPY TO command, allowing
users to export query results or table data directly as a stream of JSON
objects (one per line, NDJSON style).
 
The JSON format is currently supported only for COPY TO operations; it
is not available for COPY FROM.
 
JSON format is incompatible with some standard text/CSV formatting
options, including HEADER, DEFAULT, NULL, DELIMITER, FORCE QUOTE,
FORCE NOT NULL, and FORCE NULL.
 
Column list support is included: when a column list is specified, only
the named columns are emitted in each JSON object.
 
Regression tests covering valid JSON exports and error handling for
incompatible options have been added to src/test/regress/sql/copy.sql.
 
Author: Joe Conway <mail@joeconway.com>
Author: jian he <jian.universality@gmail.com>
Co-Authored-By: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Andrey M. Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>
Reviewed-by: Davin Shearer <davin@apache.org>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/CALvfUkBxTYy5uWPFVwpk_7ii2zgT07t3d-yR_cy4sfrrLU%3Dkcg%40mail.gmail.com
Discussion: https://postgr.es/m/6a04628d-0d53-41d9-9e35-5a8dc302c34c@joeconway.com

Continue reading Waiting for PostgreSQL 19 – json format for COPY TO

Waiting for PostgreSQL 19 – Add support for EXCEPT TABLE in ALTER PUBLICATION.

On 20th of March 2026, Amit Kapila committed patch:

Add support for EXCEPT TABLE in ALTER PUBLICATION.
 
Following commit fd366065e0, which added EXCEPT TABLE support to
CREATE PUBLICATION, this commit extends ALTER PUBLICATION to allow
modifying the exclusion list.
 
New Syntax:
ALTER PUBLICATION name SET  publication_all_object [, ... ]
 
where publication_all_object is one of:
ALL TABLES [ EXCEPT TABLE ( except_table_object [, ... ] ) ]
ALL SEQUENCES
 
If the EXCEPT clause is provided, the existing exclusion list in
pg_publication_rel is replaced with the specified relations. If the
EXCEPT clause is omitted, any existing exclusions for the publication
are cleared. Similarly, SET ALL SEQUENCES updates
 
Note that because this is a SET command, specifying only one object
type (e.g., SET ALL SEQUENCES) will reset the other unspecified flags
(e.g., setting puballtables to false).
 
Consistent with CREATE PUBLICATION, only root partitioned tables or
standard tables can be specified in the EXCEPT list. Specifying a
partition child will result in an error.
 
Author: vignesh C <vignesh21@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Discussion: https://postgr.es/m/CALDaNm3=JrucjhiiwsYQw5-PGtBHFONa6F7hhWCXMsGvh=tamA@mail.gmail.com

Continue reading Waiting for PostgreSQL 19 – Add support for EXCEPT TABLE in ALTER PUBLICATION.

Waiting for PostgreSQL 19 – Add pg_plan_advice contrib module.

On 12nd of March 2026, Robert Haas committed patch:

Add pg_plan_advice contrib module.
 
Provide a facility that (1) can be used to stabilize certain plan choices
so that the planner cannot reverse course without authorization and
(2) can be used by knowledgeable users to insist on plan choices contrary
to what the planner believes best. In both cases, terrible outcomes are
possible: users should think twice and perhaps three times before
constraining the planner's ability to do as it thinks best; nevertheless,
there are problems that are much more easily solved with these facilities
than without them.
 
This patch takes the approach of analyzing a finished plan to produce
textual output, which we call "plan advice", that describes key
decisions made during plan; if that plan advice is provided during
future planning cycles, it will force those key decisions to be made in
the same way.  Not all planner decisions can be controlled using advice;
for example, decisions about how to perform aggregation are currently
out of scope, as is choice of sort order. Plan advice can also be edited
by the user, or even written from scratch in simple cases, making it
possible to generate outcomes that the planner would not have produced.
Partial advice can be provided to control some planner outcomes but not
others.
 
Currently, plan advice is focused only on specific outcomes, such as
the choice to use a sequential scan for a particular relation, and not
on estimates that might contribute to those outcomes, such as a
possibly-incorrect selectivity estimate. While it would be useful to
users to be able to provide plan advice that affects selectivity
estimates or other aspects of costing, that is out of scope for this
commit.
 
Reviewed-by: Lukas Fittl <lukas@fittl.com>
Reviewed-by: Jakub Wartak <jakub.wartak@enterprisedb.com>
Reviewed-by: Greg Burd <greg@burd.me>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Haibo Yan <tristan.yim@gmail.com>
Reviewed-by: Dian Fay <di@nmfay.com>
Reviewed-by: Ajay Pal <ajay.pal.k@gmail.com>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com>
Discussion: http://postgr.es/m/CA+TgmoZ-Jh1T6QyWoCODMVQdhTUPYkaZjWztzP1En4=ZHoKPzw@mail.gmail.com

Continue reading Waiting for PostgreSQL 19 – Add pg_plan_advice contrib module.

Waiting for PostgreSQL 19 – Introduce the REPACK command

On 10th of March 2026, Álvaro Herrera committed patch:

Introduce the REPACK command
 
REPACK absorbs the functionality of VACUUM FULL and CLUSTER in a single
command.  Because this functionality is completely different from
regular VACUUM, having it separate from VACUUM makes it easier for users
to understand; as for CLUSTER, the term is heavily overloaded in the
IT world and even in Postgres itself, so it's good that we can avoid it.
 
We retain those older commands, but de-emphasize them in the
documentation, in favor of REPACK; the difference between VACUUM FULL
and CLUSTER (namely, the fact that tuples are written in a specific
ordering) is neatly absorbed as two different modes of REPACK.
 
This allows us to introduce further functionality in the future that
works regardless of whether an ordering is being applied, such as (and
especially) a concurrent mode.
 
Author: Antonin Houska <ah@cybertec.at>
Reviewed-by: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Robert Treat <rob@xzilla.net>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/82651.1720540558@antos
Discussion: https://postgr.es/m/202507262156.sb455angijk6@alvherre.pgsql

Continue reading Waiting for PostgreSQL 19 – Introduce the REPACK command

Waiting for PostgreSQL 19 – Allow table exclusions in publications via EXCEPT TABLE.

On 4th of March 2026, Amit Kapila committed patch:

Allow table exclusions in publications via EXCEPT TABLE.
 
Extend CREATE PUBLICATION ... FOR ALL TABLES to support the EXCEPT TABLE
syntax. This allows one or more tables to be excluded. The publisher will
not send the data of excluded tables to the subscriber.
 
To support this, pg_publication_rel now includes a prexcept column to flag
excluded relations. For partitioned tables, the exclusion is applied at
the root level; specifying a root table excludes all current and future
partitions in that tree.
 
Follow-up work will implement ALTER PUBLICATION support for managing these
exclusions.
 
Author: vignesh C <vignesh21@gmail.com>
Author: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Reviewed-by: Ashutosh Sharma <ashu.coek88@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Discussion: https://postgr.es/m/CALDaNm3=JrucjhiiwsYQw5-PGtBHFONa6F7hhWCXMsGvh=tamA@mail.gmail.com

Continue reading Waiting for PostgreSQL 19 – Allow table exclusions in publications via EXCEPT TABLE.

Waiting for PostgreSQL 19 – Add non-text output formats to pg_dumpall

On 26th of February 2026, Andrew Dunstan committed patch:

Add non-text output formats to pg_dumpall
 
pg_dumpall can now produce output in custom, directory, or tar formats
in addition to plain text SQL scripts. When using non-text formats,
pg_dumpall creates a directory containing:
- toc.glo: global data (roles and tablespaces) in custom format
- map.dat: mapping between database OIDs and names
- databases/: subdirectory with per-database archives named by OID
 
pg_restore is extended to handle these pg_dumpall archives, restoring
globals and then each database. The --globals-only option can be used
to restore only the global objects.
 
This enables parallel restore of pg_dumpall output and selective
restoration of individual databases from a cluster-wide backup.
 
Author: Mahendra Singh Thalor <mahi6run@gmail.com>
Co-Author: Andrew Dunstan <andrew@dunslane.net>
Reviewed-By: Tushar Ahuja <tushar.ahuja@enterprisedb.com>
Reviewed-By: Jian He <jian.universality@gmail.com>
Reviewed-By: Vaibhav Dalvi <vaibhav.dalvi@enterprisedb.com>
Reviewed-By: Srinath Reddy <srinath2133@gmail.com>
Discussion: https://postgr.es/m/cb103623-8ee6-4ba5-a2c9-f32e3a4933fa@dunslane.net

Continue reading Waiting for PostgreSQL 19 – Add non-text output formats to pg_dumpall

Waiting for PostgreSQL 19 – Allow log_min_messages to be set per process type

On 9th of February 2026, Álvaro Herrera committed patch:

Allow log_min_messages to be set per process type
 
Change log_min_messages from being a single element to a comma-separated
list of type:level elements, with 'type' representing a process type,
and 'level' being a log level to use for that type of process.  The list
must also have a freestanding level specification which is used for
process types not listed, which convenientely makes the whole thing
backwards-compatible.
 
Some choices made here could be contested; for instance, we use the
process type `backend` to affect regular backends as well as dead-end
backends and the standalone backend, and `autovacuum` means both the
launcher and the workers.  I think it's largely sensible though, and it
can easily be tweaked if desired.
 
Author: Euler Taveira <euler@eulerto.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Tan Yang <332696245@qq.com>
Discussion: https://postgr.es/m/e85c6671-1600-4112-8887-f97a8a5d07b2@app.fastmail.com

Continue reading Waiting for PostgreSQL 19 – Allow log_min_messages to be set per process type

Waiting for PostgreSQL 19 – psql: Add %i prompt escape to indicate hot standby status.

On 3rd of February 2026, Fujii Masao committed patch:

psql: Add %i prompt escape to indicate hot standby status.
 
This commit introduces a new prompt escape %i for psql, which shows
whether the connected server is operating in hot standby mode. It
expands to standby if the server reports in_hot_standby = on, and
primary otherwise.
 
This is useful for distinguishing standby servers from primary ones
at a glance, especially when working with multiple connections in
replicated environments where libpq's multi-host connection strings
are used.
 
Author: Jim Jones <jim.jones@uni-muenster.de>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Greg Sabino Mullane <htamfids@gmail.com>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Discussion: https://www.postgresql.org/message-id/flat/016f6738-f9a9-4e98-bb5a-e1e4b9591d46@uni-muenster.de

Continue reading Waiting for PostgreSQL 19 – psql: Add %i prompt escape to indicate hot standby status.

Waiting for PostgreSQL 19 – Implement ALTER TABLE … MERGE/SPLIT PARTITIONS … command

On 14th of December 2025, Alexander Korotkov committed patch:

Implement ALTER TABLE ... MERGE PARTITIONS ... command
 
This new DDL command merges several partitions into a single partition of the
target table.  The target partition is created using the new
createPartitionTable() function with the parent partition as the template.
 
This commit comprises a quite naive implementation which works in a single
process and holds the ACCESS EXCLUSIVE LOCK on the parent table during all
the operations, including the tuple routing.  This is why this new DDL
command can't be recommended for large partitioned tables under a high load.
However, this implementation comes in handy in certain cases, even as it is.
Also, it could serve as a foundation for future implementations with less
locking and possibly parallelism.
 
Discussion: https://postgr.es/m/c73a1746-0cd0-6bdd-6b23-3ae0b7c0c582%40postgrespro.ru
Author: Dmitry Koval <d.koval@postgrespro.ru>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Tender Wang <tndrwang@gmail.com>
Co-authored-by: Richard Guo <guofenglinux@gmail.com>
Co-authored-by: Dagfinn Ilmari Mannsaker <ilmari@ilmari.org>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Co-authored-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Robert Haas <rhaas@postgresql.org>
Reviewed-by: Stephane Tachoires <stephane.tachoires@gmail.com>
Reviewed-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Daniel Gustafsson <dgustafsson@postgresql.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>

and then, mere seconds later, he also committed second patch:

Implement ALTER TABLE ... SPLIT PARTITION ... command
 
This new DDL command splits a single partition into several partitions.  Just
like the ALTER TABLE ... MERGE PARTITIONS ... command, new partitions are
created using the createPartitionTable() function with the parent partition
as the template.
 
This commit comprises a quite naive implementation which works in a single
process and holds the ACCESS EXCLUSIVE LOCK on the parent table during all
the operations, including the tuple routing.  This is why the new DDL command
can't be recommended for large, partitioned tables under high load.  However,
this implementation comes in handy in certain cases, even as it is.  Also, it
could serve as a foundation for future implementations with less locking and
possibly parallelism.
 
Discussion: https://postgr.es/m/c73a1746-0cd0-6bdd-6b23-3ae0b7c0c582%40postgrespro.ru
Author: Dmitry Koval <d.koval@postgrespro.ru>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Tender Wang <tndrwang@gmail.com>
Co-authored-by: Richard Guo <guofenglinux@gmail.com>
Co-authored-by: Dagfinn Ilmari Mannsaker <ilmari@ilmari.org>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Co-authored-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Robert Haas <rhaas@postgresql.org>
Reviewed-by: Stephane Tachoires <stephane.tachoires@gmail.com>
Reviewed-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Daniel Gustafsson <dgustafsson@postgresql.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>

Continue reading Waiting for PostgreSQL 19 – Implement ALTER TABLE … MERGE/SPLIT PARTITIONS … command

Waiting for PostgreSQL 19 – Sequence synchronization in logical replication.

First, on 9th of October 2025, Amit Kapila committed patch:

Add "ALL SEQUENCES" support to publications.
 
This patch adds support for the ALL SEQUENCES clause in publications,
enabling synchronization/replication of all sequences that is useful for
upgrades.
 
Publications can now include all sequences via FOR ALL SEQUENCES.
psql enhancements:
\d shows publications for a given sequence.
\dRp indicates if a publication includes all sequences.
 
ALL SEQUENCES can be combined with ALL TABLES, but not with other options
like TABLE or TABLES IN SCHEMA. We can extend support for more granular
clauses in future.
 
The view pg_publication_sequences provides information about the mapping
between publications and sequences.
 
This patch enables publishing of sequences; subscriber-side support will
be added in upcoming patches.
 
Author: vignesh C <vignesh21@gmail.com>
Author: Tomas Vondra <tomas@vondra.me>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com

And then, on 5th of November 2025, he also committed patch:

Add sequence synchronization for logical replication.
 
This patch introduces sequence synchronization. Sequences that are synced
will have 2 states:
   - INIT (needs [re]synchronizing)
   - READY (is already synchronized)
 
A new sequencesync worker is launched as needed to synchronize sequences.
A single sequencesync worker is responsible for synchronizing all
sequences. It begins by retrieving the list of sequences that are flagged
for synchronization, i.e., those in the INIT state. These sequences are
then processed in batches, allowing multiple entries to be synchronized
within a single transaction. The worker fetches the current sequence
values and page LSNs from the remote publisher, updates the corresponding
sequences on the local subscriber, and finally marks each sequence as
READY upon successful synchronization.
 
Sequence synchronization occurs in 3 places:
1) CREATE SUBSCRIPTION
    - The command syntax remains unchanged.
    - The subscriber retrieves sequences associated with publications.
    - Published sequences are added to pg_subscription_rel with INIT
      state.
    - Initiate the sequencesync worker to synchronize all sequences.
 
2) ALTER SUBSCRIPTION ... REFRESH PUBLICATION
    - The command syntax remains unchanged.
    - Dropped published sequences are removed from pg_subscription_rel.
    - Newly published sequences are added to pg_subscription_rel with INIT
      state.
    - Initiate the sequencesync worker to synchronize only newly added
      sequences.
 
3) ALTER SUBSCRIPTION ... REFRESH SEQUENCES
    - A new command introduced for PG19 by f0b3573c3a.
    - All sequences in pg_subscription_rel are reset to INIT state.
    - Initiate the sequencesync worker to synchronize all sequences.
    - Unlike "ALTER SUBSCRIPTION ... REFRESH PUBLICATION" command,
      addition and removal of missing sequences will not be done in this
      case.
 
Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Hou Zhijie <houzj.fnst@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com

Continue reading Waiting for PostgreSQL 19 – Sequence synchronization in logical replication.